A. Columella percurrent; capillitium from a disk at the apex1. Enerthenema
B. Columella scarce reaching the centre of the sporangium.
a. Capillitium not forming a net2. Clastoderma
b. Capillitium forming an intricate net3. Lamproderma
c. Minute, capillitium rudimentary4. Echinostelium

1. Enerthenema Bowman

Sporangia stipitate, the stipe extended as a columella, which entirely traverses the sporangium and forms at the apex an expanded disk; from this depends the capillitium.

Key to the Species of Enerthenema

A. Spores free1. E. papillatum
B. Spores in clusters2. E. berkeleyanum

1. Enerthenema papillatum (Pers.) Rost.

[Plate V.], Fig. 3.